A compensating sealed plug valve

Abstract

The present invention discloses a compensable sealed plug valve, comprising a valve body, a valve cover and a valve stem, wherein a valve cavity connected to an inlet end and a discharge end is arranged inside the valve body, a plug body is arranged at one end of the valve stem in the valve cavity, a bushing is arranged between the plug body and the valve body, the cross-sectional area of ​​the end of the plug body away from the valve stem is smaller than the cross-sectional area of ​​the end close to the valve stem, the end of the valve stem away from the plug body is key-connected with a driving device that can drive the valve stem to rotate, an adjusting pressure plate is arranged at one end of the valve stem outside the valve body, a first fastener is penetrated on one side of the adjusting pressure plate, and one end of the first fastener is threadedly matched with the valve cover. The present invention has the following advantages and effects: the plug valve has a compensable sealing structure, which can solve the problem of sealing failure due to wear between the plug and the bushing after long-term use, thereby extending the service life of the plug valve.

Description

Technical Field

[0001] The invention relates to a plug valve, in particular to a compensable sealing plug valve. Background Art

[0002] The plug valve is a rotary valve with a closing piece or plunger shape. It is a valve that can be opened or closed by rotating 90 degrees to connect or separate the channel opening on the valve plug with the channel opening on the valve body. The shape of its valve plug can be cylindrical or conical, and the channel can be trapezoidal.

[0003] The Chinese patent with the announcement number CN204961883U discloses a plug valve, including a valve body, a plug and a valve cover, wherein a valve cavity is arranged in the valve body, the plug is located in the valve cavity, a plug rod is connected to the top of the plug, the valve body is made of alloy steel, the plug is made of ceramic, a cylindrical fit is formed between the plug and the valve body, a rotating bushing is provided on the contact surface between the plug and the valve body, a sealing ring is also provided on the top of the rotating bushing, a pressure cap is provided on the top of the sealing ring, the pressure cap presses the sealing ring on the top of the plug, a connecting channel is provided on the plug, and the size of the inlet and outlet of the connecting channel matches the size of the valve cavity channel. This prior art realizes the sealing fit between the plug and the valve body by using a rotating bushing, and effectively prevents leakage of the medium.

[0004] However, during the long-term opening and closing process of the plug, the sealing surface on the bushing in contact with the plug is prone to wear, resulting in failure of the seal between the plug and the bushing, and further leakage, so there is room for improvement. Summary of the invention

[0005] The object of the present invention is to provide a compensable sealed plug valve, which has a compensable sealing structure and can solve the problem of sealing failure due to wear between the plug and the bushing after long-term use, thereby extending the service life of the plug valve.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions: a compensable sealed plug valve, comprising a valve body, a valve cover and a valve stem, wherein a valve cavity connected to an inlet end and a discharge end is arranged inside the valve body, a plug body is arranged at one end of the valve stem in the valve cavity, a sleeve is arranged between the plug body and the valve body, the cross-sectional area of ​​the end of the plug body away from the valve stem is smaller than the cross-sectional area close to the end of the valve stem, the end of the valve stem away from the plug body is key-connected with a driving device that can drive the valve stem to rotate, an adjusting pressure plate is arranged at one end of the valve stem outside the valve body, a first fastener is penetrated through one side of the adjusting pressure plate, and one end of the first fastener is threadedly matched with the valve cover.

[0007] The present invention is further configured as follows: a limiting groove is provided at one end of the valve stem outside the valve body, a split ring is provided in the limiting groove, one end of the split ring passes through the limiting groove, the adjusting pressure plate is sleeved on the valve stem and the bottom of the adjusting pressure plate abuts against the split ring exposed outside the limiting groove.

[0008] The present invention is further configured as follows: a sealing packing assembly is arranged between the valve stem and the valve cover, and the sealing packing assembly includes a second gasket, a packing pad, a first gasket and a packing sleeve arranged in sequence from bottom to top, and the second gasket is abutted against the valve cover on one side away from the packing pad.

[0009] The present invention is further configured as follows: a compensation mechanism is provided on the valve cover, which can drive the sealing packing assembly to compress so as to increase the sealing performance between the valve cover and the valve stem; the compensation mechanism includes a packing pressure plate abutting against the upper end surface of the packing sleeve; a second fastener is passed through one side of the packing pressure plate, and one end of the second fastener cooperates with the valve cover thread.

[0010] A further configuration of the present invention is that the plug body is configured in a truncated cone or a cone shape.

[0011] The present invention is further configured as follows: a sealing compensation pressure plate is fixedly connected to one end of the valve stem outside the valve body, the bottom of the sealing compensation pressure plate abuts against the upper end surface of the sealing packing assembly, a third fastener is passed through one side of the sealing compensation pressure plate, and one end of the third fastener cooperates with the valve cover thread.

[0012] The present invention is further configured as follows: the plug body, the valve cover and the valve body together form a gap around which the plug body can rotate.

[0013] The present invention is further configured as follows: it also includes a safety mechanism, the safety mechanism includes a telescopic tube assembly, one end of the telescopic tube assembly is fixedly connected to the valve stem, the other end of the telescopic tube assembly is fixedly connected to the sealing compensation pressure plate, the telescopic tube assembly has a cavity inside, and the cavity contains a plurality of expansion beads that will expand when encountering a medium volume; a conduit is penetrated on one side of the sealing compensation pressure plate, one end of the conduit is connected to the internal cavity of the telescopic tube assembly, and the other end of the conduit passes through the valve cover and is connected to the gap.

[0014] The present invention is further configured as follows: the telescopic tube assembly includes a telescopic sleeve seat fixedly connected to the valve stem, the inner wall of the telescopic sleeve seat is horizontally slidably connected to a telescopic sleeve, the inner wall of the telescopic sleeve is horizontally slidably connected to a sliding sleeve, one end of the sliding sleeve is fixedly connected to a sealing compensation pressure plate, the outer walls of the telescopic sleeve and the sliding sleeve close to the telescopic sleeve seat are provided with an outer edge, and the telescopic sleeve seat and the telescopic sleeve close to the sliding sleeve are provided with an inner edge for resisting the outer edge.

[0015] The present invention is further configured as follows: the medium may be an aqueous medium or an oily medium, and the expansion beads may be made of a highly water-absorbent resin or a highly oil-absorbent resin.

[0016] In summary, the present invention has the following beneficial effects: after long-term use of the plug valve, the sealing surface of the bushing and the plug body will be worn, resulting in an increased probability of leakage. At this time, the operator only needs to rotate the first fastener on the adjusting plate so that one end of the first fastener is screwed into the valve cover. Then the adjusting plate is driven to move in the direction of the valve cover. It should be particularly noted that the valve stem in the present application is connected to the drive device by a key, and the valve stem can move axially and is always driven by the drive device. During the movement of the adjusting plate, the valve stem and the plug body at one end of the valve stem will be synchronously driven to move in the direction of the bushing, and the plug body is a structure with one end larger and the other end smaller, and the cross-sectional area of ​​the end away from the valve stem is smaller than the cross-sectional area of ​​the end close to the valve stem. As a result, when the plug body moves in the direction of the bushing, the contact area between the plug body and the bushing is gradually increased, so that the plug body and the bushing fit tightly to increase the sealing pressure ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 1 is a schematic diagram of the structure of the plug valve of the first embodiment;

[0018] Figure 2 yes Figure 1 A partial enlarged schematic diagram of the middle A area;

[0019] Figure 3 is a schematic structural diagram of the plug valve of Example 2;

[0020] Figure 4 yes Figure 3 A schematic diagram of the structure of the middle telescopic tube assembly;

[0021] Figure 5 yes Figure 4 Schematic diagram of the structural explosion.

[0022] : Illustrations: 1. valve body; 2. valve cover; 3. valve stem; 4. plug body; 5. driving device; 6. adjusting pressure plate; 7. first fastener; 8. limiting groove; 9. split ring; 10. sealing packing assembly; 11. second gasket; 12. packing pad; 13. first gasket; 14. packing sleeve; 15. compensation mechanism; 16. packing pressure plate; 17. second fastener; 18. bracket; 19. sealing compensation pressure plate; 20. third fastener; 21. gap; 22. safety mechanism; 23. telescopic tube assembly; 24. expansion bead; 25. catheter; 26. telescopic sleeve; 27. telescopic sleeve; 28. sliding sleeve; 29. ​​outer edge; 30. inner edge; 31. bushing; 32. butterfly spring. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0024] Embodiment 1:

[0025] like Figure 1-Figure 2 As shown, a compensable sealed plug valve includes a valve body 1, a valve cover 2 and a valve stem 3. A valve cavity connected to an inlet end and a discharge end is arranged inside the valve body 1. A plug body 4 is arranged at one end of the valve stem 3 in the valve cavity. A bushing 31 is arranged between the plug body 4 and the valve body. The cross-sectional area of ​​the end of the plug body 4 away from the valve stem 3 is smaller than the cross-sectional area of ​​the end close to the valve stem 3.

[0026] The end of the valve stem 3 away from the plug body 4 is keyed to a driving device 5 that can drive the valve stem 3 to rotate. An adjusting plate 6 is provided at one end of the valve stem 3 outside the valve body 1, and a first fastener 7 is penetrated on one side of the adjusting plate 6, and one end of the first fastener 7 is threadedly matched with the valve cover 2.

[0027] After long-term use of the plug valve, the sealing surface of the bushing 31 and the plug body 4 will be worn, resulting in an increased probability of leakage. At this time, the operator only needs to rotate the first fastener 7 on the regulating plate 6 so that one end of the first fastener 7 is screwed into the valve cover 2. Then the regulating plate 6 is driven to move in the direction of the valve cover 2. It should be noted that the valve stem 3 in the present application is connected to the driving device 5 by a key, and the valve stem 3 can move axially and is always driven by the driving device 5. During the movement of the regulating plate 6, the valve stem 3 and the plug body 4 at one end of the valve stem 3 will be synchronously driven to move in the direction of the bushing 31, and the plug body 4 is a structure with one end larger than the other end, and the cross-sectional area of ​​the end away from the valve stem 3 is smaller than the cross-sectional area of ​​the end close to the valve stem 3. As a result, when the plug body 4 moves in the direction of the bushing 31, the contact area between the plug body 4 and the bushing 31 will gradually increase, so that the plug body 4 and the bushing 31 fit closely to increase the sealing pressure ratio.

[0028] Furthermore, the present application can also realize that the adjusting pressure plate 6 and the valve stem 3 are movably matched. A limiting groove 8 is provided at one end of the valve stem 3 outside the valve body 1, and a split ring 9 is provided in the limiting groove 8, and one end of the split ring 9 passes through the limiting groove 8. The adjusting pressure plate 6 is sleeved on the valve stem 3, and the bottom of the adjusting pressure plate 6 abuts against the split ring 9 exposed outside the limiting groove 8.

[0029] Through the above arrangement, the split ring 9 and the adjusting pressure plate 6 are detachable. When the sealing pressure ratio between the plug body 4 and the bushing 31 needs to be adjusted, there is no need to stop the work and disassemble the valve. The sealing performance of the components inside the valve body 1 can be adjusted by simply installing the above components, which greatly facilitates operation and use.

[0030] Furthermore, a sealing packing assembly 10 is provided between the valve stem 3 and the valve cover 2. The sealing packing assembly 10 includes a second gasket 11, a packing pad 12, a first gasket 13 and a packing gland 14 which are arranged in sequence from bottom to top. The side of the second gasket 11 away from the packing pad 12 abuts against the valve cover 2. By providing the sealing packing assembly 10, the sealing performance between the valve stem 3 and the valve cover 2 can be increased, thereby preventing the medium from overflowing from between the valve stem 3 and the valve cover 2 and increasing the stability of medium transmission.

[0031] Furthermore, the valve cover 2 is provided with a compensation mechanism 15 which can drive the sealing packing assembly 10 to be compressed so as to increase the sealing performance between the valve cover 2 and the valve stem 3 .

[0032] Furthermore, the compensation mechanism 15 includes a packing pressure plate 16 that abuts against the upper end surface of the packing sleeve 14, and a second fastener 17 is penetrated on one side of the packing pressure plate 16, and one end of the second fastener 17 is threadedly matched with the valve cover 2. By rotating the second fastener 17, one end of the second fastener 17 is screwed into the valve cover 2, thereby driving the packing pressure plate 16 to move toward the valve cover 2, and then pressing the packing sleeve 14, so that the sealing packing assembly 10 is compressed to increase the sealing performance between the valve cover 2 and the valve stem 3. It should be particularly noted that the two ends of the sealing packing assembly 10 are respectively abutted by the packing pressure plate 16 and the valve cover 2, the valve cover 2 is stationary, and the packing pressure plate 16 is movable. When the distance between the packing pressure plate 16 and the valve cover 2 is reduced, the sealing packing assembly 10 can be squeezed, thereby achieving the function of compensating the sealing performance between the valve stem 3 and the valve cover 2.

[0033] Furthermore, the plug body 4 is configured in a truncated cone or a cone shape.

[0034] Furthermore, a bracket 18 is provided on the valve cover 2 , the driving device 5 is mounted on the bracket 18 , and one end of the valve stem 3 passes through the bracket 18 and is key-connected with the driving device 5 .

[0035] Furthermore, a butterfly spring 32 is provided between the regulating plate 6 and the first fastener 7, one end of the butterfly spring 32 is fixedly connected to the regulating plate 6, and the other end of the butterfly spring 32 is fixedly connected to the first fastener 7. The butterfly spring 32 is in a compressed state when the plug valve has no leakage.

[0036] When the plug valve leaks, the sealing pressure inside the valve after wear is less than the required pressure. First, the butterfly spring 32 releases the spring pressure to move the valve stem toward the bushing, thereby ensuring the sealing performance and extending the service life of the valve. At the same time, when the sealing pressure released by the butterfly spring is not enough to ensure the sealing performance of the valve, the first fastener 7 is tightened to apply external force to solve the valve online leakage. In the above, the regulating plate 6 and the butterfly spring 32 form a sealing pressure compensation function that combines self-force and applied force.

[0037] Furthermore, one end of the plug body 4 is in contact with the valve cover 2. The present application adopts a contact valve cover plug body structure. When initially installed, the valve cover 2 directly applies force to the large flat end of the plug body 4, thereby increasing the sealing pressure ratio of the valve, and also effectively eliminating the phenomenon of sealing pressure ratio loss between the plug body 4 and the bushing 31 caused by the plug body 4 moving in the axial direction of the valve stem 3 due to the medium pressure difference.

[0038] Embodiment 2:

[0039] The difference from the embodiment is that: Figure 3-Figure 5 As shown, a sealing compensation plate 19 is fixedly connected to one end of the valve stem 3 outside the valve body 1, and the bottom of the sealing compensation plate 19 abuts against the upper end surface of the sealing packing assembly 10. A third fastener 20 is penetrated on one side of the sealing compensation plate 19, and one end of the third fastener 20 is threadedly matched with the valve cover 2.

[0040] By setting the sealing compensation plate 19 and the third fastener 20 as described above, when one end of the third fastener 20 is screwed into the valve cover 2 to reduce the distance between the sealing compensation plate 19 and the valve cover 2, the valve stem 3 and the plug body 4 at one end of the valve stem 3 can be synchronously driven to move toward the bushing 31 to increase the sealing contact surface between the plug body 4 and the bushing 31 and increase the sealing specific pressure. In addition, the sealing compensation plate 19 can also squeeze the sealing packing assembly 10 to increase the sealing performance between the valve stem 3 and the valve cover 2. The above-mentioned sealing performance between the valve stem 3 and the valve cover 2, and the plug body 4 and the bushing 31 can be achieved with only one sealing compensation plate 19.

[0041] Furthermore, the plug body 4, the valve cover 2 and the valve body 1 form a gap 21 around which the plug body 4 can rotate. Due to the sealing effect of the bushing 31 and the sealing packing assembly 10 at both ends of the gap 21, no medium in the valve cavity can enter the gap 21 in the absence of medium leakage. However, when the sealing surface between the bushing 31 and the plug body 4 wears after long-term use, which leads to medium leakage, the medium in the valve cavity will enter the gap 21. At this time, if the sealing packing assembly 10 cannot achieve the seal between the valve stem 3 and the valve cover 2, the medium will leak out of the plug valve. If the transmitted medium is a flammable, explosive, or toxic dangerous good, there will be a safety hazard that may cause an accident.

[0042] It should be noted that the above technical solutions all require manual rotation of the fasteners to strengthen the valve seal. However, the medium leakage is sudden, accidental and random. At this time, the operator has no time to strengthen the valve seal or even close the valve when the leakage occurs. Therefore, a safety mechanism 22 is needed to solve this problem.

[0043] Furthermore, a safety mechanism 22 is included, which includes a telescopic tube assembly 23, one end of which is fixedly connected to the valve stem 3, and the other end of which is fixedly connected to the sealing compensation plate 19. The telescopic tube assembly 23 has a cavity inside, and the cavity contains a plurality of expansion beads 24 that expand in volume when encountering a medium.

[0044] A conduit 25 is provided on one side of the sealing compensation pressure plate 19 , one end of the conduit 25 is communicated with the inner cavity of the telescopic tube assembly 23 , and the other end of the conduit 25 passes through the valve cover 2 and is communicated with the gap 21 .

[0045] When there is a sudden leakage danger in the valve, so that the operator has no time to close the valve, the medium in the valve will enter the gap 21 and push into the conduit 25 under the pressure of the medium in the valve, thereby pushing the medium into the cavity of the telescopic tube assembly 23 and contacting the expansion bead 24 in the cavity. The expansion bead 24 will expand when it encounters the medium, while the top valve stem 3 and the telescopic tube assemblies 23 on both sides that are in contact with the expansion bead 24 are fixed, and the telescopic tube assembly 23 can only move along its circumferential direction, and the sealing compensation plate 19 that is in contact with the expansion bead 24 is relatively movable.

[0046] It should also be noted that the two ends of the telescopic tube assembly 23 are fixedly connected to the valve stem 3 and the sealing compensation plate 19 respectively, and the telescopic tube assembly 23 will extend axially. In the process of expansion of the expansion bead 24, a force will be applied to the sealing compensation plate 19 toward the valve cover 2, thereby shortening the distance between the sealing compensation plate 19 and the valve cover 2, so as to achieve the sealing performance between the valve stem 3 and the valve cover 2, and the plug body 4 and the bushing 31.

[0047] In the above process, the valve stem 3 drives the plug body 4 to move toward the bushing 31, thereby expanding the size of the gap 21 formed by the plug body 4, the valve cover 2, and the valve body 1. Once the gap 21 is expanded, the residual medium in the conduit 25 will flow back into the gap 21. Through this process, the expansion beads 24 are gradually separated from the contact with the medium, and after the expansion beads 24 are gradually dried naturally, their volume will be reduced. In addition, the residual medium in the gap 21 will also be naturally dried.

[0048] Furthermore, the telescopic tube assembly 23 includes a telescopic sleeve 26 fixedly connected to the valve stem 3, the inner wall of the telescopic sleeve 26 is horizontally slidably connected to a telescopic sleeve 27, the inner wall of the telescopic sleeve 27 is horizontally slidably connected to a sliding sleeve 28, and one end of the sliding sleeve 28 is fixedly connected to the sealing compensation pressure plate 19.

[0049] An outer edge 29 is disposed on the outer wall of one end of the telescopic sleeve 27 and the sliding sleeve 28 close to the telescopic sleeve seat 26 , and an inner edge 30 for contacting the outer edge 29 is disposed on one end of the telescopic sleeve seat 26 and the telescopic sleeve 27 close to the sliding sleeve 28 .

[0050] Furthermore, one end of the expansion bead 24 contacts the sealing compensation plate 19 .

[0051] Furthermore, the medium may be an aqueous medium or an oily medium, and the corresponding expansion beads 24 may be made of a highly water-absorbent resin or a highly oil-absorbent resin.

[0052] The specific embodiments are merely explanations of the present invention and are not limitations of the present invention. After reading this specification, those skilled in the art may make modifications to the embodiments without any creative contribution as needed. However, such modifications are protected by the patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A compensable sealed plug valve, comprising a valve body (1), a valve cover (2) and a valve stem (3), wherein a valve cavity communicating with an inlet end and a discharge end is arranged inside the valve body (1), a plug body (4) is arranged at one end of the valve stem (3) in the valve cavity, a bushing (31) is arranged between the plug body (4) and the valve body (1), and a driving device (5) capable of driving the valve stem (3) to rotate is key-connected at one end of the valve stem (3) away from the plug body (4), wherein the valve stem (3) is characterized in that: The cross-sectional area of ​​the end of the plug body (4) away from the valve stem (3) is smaller than the cross-sectional area of ​​the end close to the valve stem (3); an adjusting pressure plate (6) is provided at one end of the valve stem (3) outside the valve body (1); a first fastener (7) is passed through one side of the adjusting pressure plate (6); one end of the first fastener (7) is threadedly engaged with the valve cover (2); The valve stem (3) is provided with a limiting groove (8) at one end outside the valve body (1), and a split ring (9) is provided in the limiting groove (8), and one end of the split ring (9) extends out of the limiting groove (8); the regulating pressure plate (6) is sleeved on the valve stem (3), and the bottom of the regulating pressure plate (6) abuts against the split ring (9) exposed outside the limiting groove (8); A sealing packing assembly (10) is arranged between the valve stem (3) and the valve cover (2), and the sealing packing assembly (10) comprises a second gasket (11), a packing pad (12), a first gasket (13) and a packing gland (14) which are arranged in sequence from bottom to top, and a side of the second gasket (11) away from the packing pad (12) is in contact with the valve cover (2); One end of the valve stem (3) outside the valve body (1) is fixedly connected to a sealing compensation plate (19), the bottom of the sealing compensation plate (19) abuts against the upper end surface of the sealing packing assembly (10), and a third fastener (20) is passed through one side of the sealing compensation plate (19), and one end of the third fastener (20) is threadedly engaged with the valve cover (2); The plug body (4), the valve cover (2) and the valve body (1) together form a gap (21) around which the plug body (4) can rotate; The valve body also includes a safety mechanism (22), wherein the safety mechanism (22) includes a telescopic tube assembly (23), one end of the telescopic tube assembly (23) is fixedly connected to the valve stem (3), the other end of the telescopic tube assembly (23) is fixedly connected to the sealing compensation plate (19), the telescopic tube assembly (23) has a cavity inside, and the cavity contains a plurality of expansion beads (24) that expand when encountering a medium; a conduit (25) is passed through one side of the sealing compensation plate (19), one end of the conduit (25) is connected to the cavity inside the telescopic tube assembly (23), and the other end of the conduit (25) passes through the valve cover (2) and is connected to the gap (21).

2. A compensable sealing plug valve according to claim 1, characterized in that: The valve cover (2) is provided with a compensation mechanism (15) which can drive the sealing packing assembly (10) to be compressed so as to increase the sealing performance between the valve cover (2) and the valve stem (3); the compensation mechanism (15) includes a packing pressure plate (16) which abuts against the upper end surface of the packing sleeve (14); a second fastener (17) is passed through one side of the packing pressure plate (16); one end of the second fastener (17) is threadedly engaged with the valve cover (2).

3. A compensable sealing plug valve according to claim 1, characterized in that: The plug body (4) is arranged in a truncated cone shape or a conical shape.

4. A compensable sealing plug valve according to claim 1, characterized in that: The telescopic tube assembly (23) includes a telescopic sleeve (26) fixedly connected to the valve stem (3); the inner wall of the telescopic sleeve (26) is horizontally slidably connected to a telescopic sleeve (27); the inner wall of the telescopic sleeve (27) is horizontally slidably connected to a sliding sleeve (28); one end of the sliding sleeve (28) is fixedly connected to a sealing compensation pressure plate (19); an outer edge (29) is provided on the outer wall of one end of the telescopic sleeve (27) and the sliding sleeve (28) close to the telescopic sleeve (26); and an inner edge (30) for contacting the outer edge (29) is provided on one end of the telescopic sleeve (26) and the telescopic sleeve (27) close to the sliding sleeve (28).

5. A compensable sealing plug valve according to claim 4, characterized in that: The medium may be an aqueous medium or an oily medium, and the expansion beads (24) may be made of a highly water-absorbent resin or a highly oil-absorbent resin.

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